Method and apparatus for manipulating selvage warp and weft yarns



v. SVAFY June .24, 1969 Sheet Filed Feb 16, 1967 INVENTOR. M We? a xwz r 1/ V. SVATY METHOD AND APPARATUS FOR MANIPULATING SELVAGE WARP AND WEFT YARNS Sheet Filed Feb. 16, 1967 INVENTOR.

V. SVATY June 24, 1969 METHOD AND APPARATUS FOR MANIPULAIING SELVAGE WARP AND WEI-T YARNS Sheet Filed Feb. 16. 1967 June 24, 1969 v. svAT"Y 3,451,436

METHOD AN! APPARATUS FOR MANlPULATING SISLVAGE WARP AND WEFT YARNS Filed Feb. 16, 1967 Sheet 4 of 4 INVENTOR ATTORNEY United States Patent US. Cl. 139-55 8 Claims ABSTRACT OF THE DISCLOSURE Method of controlling movements of a gripper in a gripper loom according to which the gripping mechanism which engages and entrains the leading end of the pick releases the pick before the leading end is moved laterally beyond the selvage so that the pick need not extend beyond the edges of the fabric. The warp yarns of the shed sides remain open until after the gripping mechanism of the gripper moves beyond the respective fabric edge so that release of the leading end of the pick can take place in the space between the lateral warp portions, whereupon the respective shed side closes.

Background of the invention The present invention relates to looms in general, and more particularly to improvements in looms of the type wherein a gripper is caused to travel through the shed and entr-ains the leading end of the weft yarn or pick.

Gripper looms are becoming increasingly popular in textile industry. However, though the efficiency of such looms is high, many problems remain to be solved in connection with forming of the selvage. Imperfections in selvage are due mainly to the presence of false selvage which must be severed or woven into the next shed with attendant losses in weft yarn.

The main reason for waste of the weft yarn which is drawn by the gripper of a gripper loom is that the gripping mechanism of the gripper must move beyond the edges of the fabric because such mechanism is used to hold the pick during interlacing of warp yarns which form the shed. The projecting leading end of the pick must be severed or woven into the next shed. For example, if the gripping mechanism of the gripper holds a portion of the pick whose length is about mm., and if the mechanism is caused to move beyond the edges of the fabric by a distance of about 10 mm., the total length of wasted weft yarn is 20 mm. However, losses in weft yarns are normally much higher because the pick-engaging mechanism of the gripper is often caused to move away from the axis of the shed before the heddle frames are moved to level position. The axis of the shed is a horizontal line at the beat-up point of the shed. Furthermore, and if the loom comprises a mechanism which takes over the leading end of the pick from the gripping mechanism of the gripper, the waste length of each pick is much greater because the gripping mechanism must be moved a greater distance from the selvage in order to provide room for entry of the mechanism which takes over the pick.

Accordingly, it is an important object of the present invention to provide a novel and improved method of manipulating the pick or weft yarn in a gripper loom in such a way that losses of weft yarn are eliminated or reduced to a minimum.

Another object of the invention is to provide a method of the just outlined characteristics which can be practiced by resorting to looms constituting simple modifications of existing gripper looms.

A further object of the invention is to provide a method of manipulating picks in gripper looms according to which 3,451,436 Patented June 24, 1969 the pick is properly held and tensioned until after the completion of the main interlacing step.

An additional object of the invention is to provide a gripper loom which can be used in the practice of my method.

Summary of the invention One feature of my invention resides in the provision of a method of manipulating the pick in a gripper loom wherein the marginal warp yarns which form part of the selvage from marginal sheds independently of the centrally located warp yarns. The method comprises the steps of moving the warp yarns apart to form a shed, gripping the leading end of a pick and drawing the pick from one end toward the other end of the shed, arresting the pick and continuously gripping its leading end while the latter is accommodated in the other end of the shed between the respective marginal warp yarns, closing the shed of the centrally located warp yarns, releasing the leading end of the pick, beating-up the pick, and closing the marginal shed formed by the marginal warp yarns at the other end of the shed. Such closing of the marginal warp sheds preferably takes place simultaneously with the closing of centrally located warp shed. The leading end of the pick is held at the apex of the shed during the changing of the centrally located warp shed.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved loom itself, however both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawing.

Brief description of the drawing FIG. 1 is a fragmentary perspective view of a loom which embodies my invention;

FIG. 2 is a side elevational view of certain component parts of the structure shown in FIG. 1;

FIG. 3 illustrates a first stage of movement of the gripper through the shed;

FIG. 4 illustrates the next-following stage;

FIG. 5 illustrates a third stage;

FIG. 6 illustrates a fourth and last stage of gripper movement;

FIG. 7 is a perspective view showing the third stage;

FIG. 8 is a fragmentary schematic elevation illustrating the operation of heddle frames in accordance with the invention; and

FIG. 9 is a fragmentary elevation illustrating means for operating the heddle frames for the warp yarns forming the central portion of the warp shed.

Description of preferred embodiments Referring first to FIGS. 1 and 2, there is shown a portion of a gripper loom with a reversible unilateral gripper .1, also called one-side gripper. This gripper is guided in a manner known per se and passes between the reeds 2 of a batten 7 and guide needles 3. After having passed through the shed 15, the gripper 1 reaches one of two turning means here shown as shuttle *boxes 4 which are turnably mounted on the batten 7 together with inserting cylinders 5 and picker sticks 6. The batten 7 is rockable with an oscillating shaft 8 which controls the operation of inserting cylinders 5 through the intermediary of a main compression cylinder 12. The piston rod 11 of the compression cylinder 12 is reciprocated by .a crank drive 9, 10 which receives motion from the shaft 8, and the connection between the cylinders 5, 12 comprises flexible conduits 13, 14 of rubber or the like. The exact mode of turning the shuttle boxes 4 and of moving the gripper 1 through the shed forms no part of the present invention. Reference may be had, for example, to my copendiug application Ser. No. 437,506, filed Mar. 5, 1965.

FIG. 2 shows certain elements of the structure of FIG. 1 in side elevation. The gripper .1 and reeds 2 are shown in two positions which are respectively indicated by solid and broken lines. In the solid-line position of the gripper 1 the gripper travels through the shed 15 between the centrally located upper and lower warp ends 16, 17. The apex or beat-up line of the shed 15 is shown at 18. Broken lines show the reeds 2 in beating-up position; the gripper 1 and needles 3 then descend to a level below the beat-up point 18 and are located adjacent to the one or the other selvage of the fabric. In other words, the gripper 1 is then located below the axis of the shed 15, such .axis being constituted by a straight horizontal line 18 at the fell of the fabric. Lowering of the gripper 1 below the apex of the shed 15 is advantageous and desirable because of the gripper 1 can be guided on one side by the needles 3. FIG. 2 shows two heddle frames 101 and 102 for forming sheds of warp yarns 16 and 17.

The gripper 1 entrains the pick or weft yarn 19 (shown in FIGS. 3 to 6) and comprises a gripping or engaging mechanism 22 which engages and releasably holds the leading end of the pick 19. As explained in connection with FIG. 2, the gripper 1 moves below the axis of the shed 15 during beating-up and is outwardly adjacent to one of the selvages. Thus, and were the mechanism 22 of the gripper 1 still attached to the pick .19 at the time the gripper assumes the broken-line position of FIG. 2, a considerable length of the pick 19 would extend beyond the respective selvage and would go to waste. The just described and rather wasteful weaving operation is typical of many presently known shuttleless looms.

In accordance with a feature of my invention, savings in weft yarn 19 can be achieved by maintaining the mechanism 22 of the gripper 1 in a marginal portion of the shed 15 until after completion of the closing of the central shed portion. This can be achieved by turning and reversing the gripper 1 while the latter leaves the shed 15.

In a conventional gripper weaving machine or loom with one, reversibly picked gripper (such a machine operates on the principle known as Novostav system), the griper 1 enters one of the two shuttle boxes 4 on opposite sides of the loom after each pass through the shed 15. The shuttle box 4 brakes the gripper and rotates therewith while the batten 7 with reed '2 moves to the beating-up position. The leading end of the pick 19 is maintained in the axis of the shed 15 while the gripper 1 turns with one of the shuttle boxes 4. Such mode of operation reduces but does not eliminate waste in weft yarn because, in presently known looms, the mechanism 22 continues to grip the pick .19 while it moves beyond the respective selvage of the fabric, i.e., a portion of the leading end of the pick 19 invariably extends laterally beyond the selvage. Such portion of the pick 19 must be severed or incorporated into the selvage.

As stated before, a feature of my invention resides in that the pick engaging mechanism 22 does not move beyond the selvages of the fabric while it still engages and holds the pick 19. Therefore, and by the simple expedient of disengaging the pick 19 from the mechanism 22 before the latter moves laterally beyond the selvage, the leading end of the pick 19 need not extend from the selvage and waste in weft yarn is eliminated with additional savings attributable to dispensal with auxiliary equipment which is needed to sever and/or otherwise process the projecting ends of picks in conventional looms.

The best mode of laying the pick 19 will now be described with reference to FIGS. 3 to 6. During the first stage which is shown in FIG. 3, the gripper 1 travels through a marginal warp shed portion, not shown, on the right side of the shed 15 and then between the upper and lower warp yarns 16, 17 of the central warp shed portion. The marginally located warp yarns 20, 21 of the selvages are controlled by heddle frames and 106 independently of the warp yarns .16, 17 which are controlled by heddle frames 101 to 104 as shown in FIG. 2 and FIG. 9. FIGS. 3-6 merely show the warp yarns 20, 21 of the left-hand selvage but it is to be understood that the warp yarns of the other selvage are controlled in the same way. The leading end of the pick 19 trails the gripper 1 and is affixed to the engaging mechanism 22.

In the next-following stage which is shown in FIG. 4, the gripper 1 has arrived at the left-hand selvage of the fabric and in the open marginal shed portion formed by warp yarns 20, 21 and its front portion has entered the shuttle box 4. The gripping mechanism 22 is still accommodated in the left-hand end of the shed 15 (between the marginal warp yarns 20, 21).

The third stage is shown in FIG. 5 and FIG. 7. The gripper 1 begins to turn with the shuttle box 4 while the batten 7 moves toward the beating-up position. At the same time, the centrally located warp yarns 16, 17 are interlaced for closing the central portion of the warp shed marginal warp yarns 20, 21 forming a marginal warp shed portion open and preferably move even fur ther away from each other. When the closing of the shed of yarns .16, 17 is completed, i.e., when the heddle frames 101 to 104, see FIGS. 2 and 8, reach their level positions, the mechanism 22 releases the leading end of the pick 19 while the leading end remains in the left-hand marginal shed portion of the shed 15, i.e., in the space between the warp yarns 20, 21, and does not project beyond the selvage. The gripper 1 penetrates deeper into the shuttle box 4.

In the fourth and last stage which is shown in FIG. 6, the gripper 1 is fully accommodated in the shuttle box 4 and the leading end of the pick 19 is fully separated from the engaging mechanism 22. The leading end is straightened out in response to movement of mechanism 22 from the position of FIG. 5 to the position of FIG. 6. The engaging mechanism 22 is shown to be .a hook engaged by a plate for clamping the leading end portion 119 of the pick. When the main portion of the pick is held by the central warp shed 16, 17, and gripper 1 moves from the position of FIG. 5 to the position of FIG. 6, the end portion of pick 19 is pulled out of the engaging mechanism at the trailing end of gripper 1. The marginal warp yarns 20, 21 .are still maintained in spacedapart position by heddle frames 105, 106 and form an open marginal warp shed portion. The beating-up step and the changing of the marginal warp shed portion 20, 21 follow. However, since early changing would require an independent control mechanism for the heddle frames 105, 106 of yarns 20, 21, it is more practical to close the marginal shed portions of such marginal warp yarns by heddle frames 105, 106 when the gripper 1 is located adjacent to the other edge of the fabric. In this way, the 10031 will form selvages 2:2 which are most frequently use The operation of the heddle frames and shifting of the gripper 1 can be carried out by mechanisms of known design which form no part of the present invention.

The conventional and standard heddle frame mechanism is used for carrying out the above-described changing of the warp yarns of the central shed portion formed by warp threads 16 and 17, and of the marginal shed portions formed by the marginal warp yarns 20 and 21 in the region of the selvage.

FIGS. 8 and 9 illustrate conventional heddle frame mechanism for forming sheds in accordance with the invention. Heddle frames 101, 102, 103, 104 form the central warp sheds of warp yarns 16 and 17, and are shown in FIG. 8 in the aligned position in which the central warp shed formed of warp yarns 16 and 17 is closed as shown in FIG. 4. Heddle frames 105 and 106 are shown in FIG. 18 for moving the marginal warp threads 20 and 21 from the position shown in FIGS. 8 and 3 opening a marginal shed portion, to a position in which the marginal shed portion is changed, corresponding to the position in which heddle frames 101 to 104 are shown in FIG. 8.

Heddle frames 101 to 104 are connected by pull rods 131 to 134 to a corresponding series of levers 141 mounted on pivot means 150 and carrying rollers 151, as shown in FIG. 9. Four cams 157, 158 are fixed on a shed forming shaft 163 and operate heddle frames .101 to 104 through rollers 151, levers 141, and rods 131 to 134 in the usual manner. Shaft 163 also carries cams 161 and 162 respectively cooperating with rollers 155, 156 carried by levers .145, 146 connected by rods 134, 136 to the marginal heddle frames 105, 106 by which the marginal warp yarns 20 and 21 are formed into marginal sheds as described with references to FIGS. 3 to 6. Corresponding marginal heddle frames, not shown, .are provided on the other side of the central warp yarns 16, 17.

The sequence of shed forming operations described with reference to FIGS. 3 to 6 is obtained by the shape and relative angular position of cams 157, 158, 161, 162 so that the conventional heddle frame mechanism shown in FIGS. 8 and 9 can be easily adapted for carrying out the above described operations.

An important advantage of the above-described procedure is that each pick 19 is of the same length and that such picks need not extend beyond or extend only slightly from the selvages. Furthermore, each pick is maintained by the partly closed warp shed under requisite tension prior to beating-up.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features which fairly constitute essential characteristics of the generic and specific aspects of my contribution to the art and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:

1. A method of weaving, comprising the steps of opening a central first warp shed portion, and marginal second and third warp shed portions on opposite sides of said central first warp shed portion; gripping the leading end of a pick and drawing the same through said second and first warp shed portions into said third warp shed portion; closing said first and second warp shed portions to secure said pick; releasing said leading end of said pick in a position located in said third warp shed portion adjacent the lateral end of the same; and closing said third warp shed portion.

2. The method of claim 1 wherein said leading end of said pick is gripped and held at the fell of the fabric at the axis of said third warp shed portion during said closing of said first and second warp shed portions.

3. The method of claim 1 including beating up said pick before closing said third warp shed portion.

4. The method of claim 1 wherein said leading end of said pick is gripped by a gripper; wherein said gripper is reversed while partly located in said third warp shed portion for releasing said leading end whereby said gripper can make the following pick insertion successively through said third, first and second warp shed portions.

'5. The method of claim 1 wherein said leading end of said pick is gripped by said gripper in the initial stage of turning said gripper to a reversed position, and released by said gripper when the extremity of said leading end is located inwardly adjacent said lateral end of said third warp shed portion.

6. The method of claim 1 wherein said free end of said pick is detachably gripped by an engaging mechanism of a gripper; and wherein said gripper is displaced while said pick is held by said first and second closed Warp sheds so that said free end is pulled out of said engaging mechanism when said gripper is displaced.

7. Gripper loom comprising first heddle frame means for forming a central first warp shed portion; second and third heddle frame means for forming, respectively, marginal second and third warp shed portions on opposite sides of said central first warp shed portion; gripper means for drawing a pick through said warp shed portions; means for operating said heddle frames for changing said first and second warp shed portions while said gripper and the leading end of a pick are located in said third warp shed portion, and for changing said first and third warp shed portions when said gripper and the leading end of another pick are located in said second warp shed portion; and control means for operating said griper to release said leading end of a pick when the same is located in one of said marginal warp shed portions.

8. Apparatus as claimed in claim 7 wherein said control means include turnable shuttle boxes located on opposite sides of said loom for receiving said gripper, and being disposed so that the leading end of said gripper enters said shuttle boxes while the trailing end of said gripper is still located in the respective marginal warp shed portion, said gripper having an engaging mechanism at the trailing end thereof for holding the leading end of a pick so that turning of said shuttle boxes causes release of the pick while the leading end thereof is located in the respective marginal warp shed portion.

References Cited UNITED STATES PATENTS 2,924,247 2/1960 Flamand 139-79 2,990,854 7/1961 Pfarrwaller 139-123 3,108,617 10/1963 Nichols 139-55 FOREIGN PATENTS 690,880 7/1964 Canada. 677,255 6/ 1939 Germany.

HENRY S. IAUDON, Primary Examiner.

US. Cl. X.R. 

